The visual appearance of source code.
# Here is an example of Python code with lots of # formatting issues including: trailing spaces, missing spaces # around operators, strange and inconsistent indentation etc. z = 'hello'+'world' def f ( a): pass
A coding style (the of rules or guidelines used when writing the source code) can drastically affect the readability, and maintainability of a program and might as well introduce bugs.
How to fix this
Defining a clearly and thoughtful coding style (based on the available ones given the programming language in use) and strictly respect it or apply it through out the implementation of a project.